Many modern surgical techniques have been developed which are employed to alleviate or obviate the stenoses that are formed when plaque builds up in a patient's vessels. For example, several balloon angioplasty devices have been proposed for insertion into a vessel to compress the stenosis and widen the passageway through the vessel. In several respects, balloon angioplasty devices afford numerous advantages over alternative methods. Foremost among these advantages is that open-heart bypass surgery can often be avoided by using angioplasty surgical techniques to relieve stenoses in the vessels that supply blood to the heart. For obvious reasons, it is preferable to avoid open heart surgery whenever possible, because such surgery, as is well known, is invasive and can consequently require significant post-operative recovery time. Accordingly, rather than many alternative procedures, it is often preferable to use relatively simpler angioplasty surgical procedures, when such procedures are feasible. Importantly, angioplasty procedures can be performed in the peripheral vessels of a patient, as well as in the vessels that supply blood to the heart.
In an angioplasty surgical procedure, the balloon of a balloon catheter is initially in a deflated configuration as it is advanced through the vasculature into a vessel and positioned next to the stenosis that is to be treated. Once the balloon has been properly positioned, fluid is infused into the balloon to expand the balloon. As the balloon expands, it dilates the stenosis in the lumen of the vessel and compresses the plaque. This causes the plaque to break up or flatten out against the vessel wall. Once the stenosis has been compressed, however, the balloon needs to be deflated. In its deflated configuration, it is then either withdrawn from the vessel or placed across another stenosis, as necessary, to restore normal blood flow through the vessel.
During the deflation of a balloon, after an angioplasty procedure and prior to its removal from the vessel, it is desirable that the balloon be deflated into a predictable configuration as evenly and as compactly as practicable to facilitate removal of the balloon through tortuous passageways of the vessel. Several polymers which are desirable for use in balloon angioplasty catheters, because of their strength, such as polyethylene terephthalate and polyethylene naphthalate, are well known for poor refold characteristics.
In light of the above, it is an object of the present invention to provide a device that is useful for collapsing a balloon into a compact pleated cross-sectional configuration during balloon deflation to facilitate removal of the balloon from a patient's body. Another object of the present invention is to provide a device that is useful for collapsing a balloon in a uniform and predictable manner during balloon deflation. Yet another object of the present invention is to provide a device which is relatively simple to manufacture, easy to use, and comparatively cost effective.